Contraceptive system and method of use

ABSTRACT

A device and method of using the device for contraception or sterilization and particularly for reversible contraception by occluding a reproductive lumen to prevent the passage of reproductive cells through the lumen for a desired period of time until the patient wishes to become fertile again and then be reopened. The occluding member preferably comprises a tubular framework formed from a shape memory material configured to be implanted in a reproductive lumen. The occluding member is implanted within a body lumen, secured to the wall of the reproductive lumen and then collapsed to collapse the wall and occlude the lumen. Alternatively, the occluding member may be collapsed upon a solid plug. The closure of the reproductive lumen may be reversed by introducing a balloon catheter and by a series of inflations of the balloon reexpanding the collapsed occluding member or by removing the plug. The occluding member and the plug may be configured to facilitate endothelialization, to provoke an inflammatory responses or to deliver a drug.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/972,857, filed Oct. 25, 2004, which is a continuation of U.S.application Ser. No. 08/770,123 filed Dec. 18, 1996, now U.S. Pat. No.7,073,504, the entireties of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Conventional contraceptive strategies generally fall within threecategories: physical barriers, drugs and surgery. While each havecertain advantages, they also suffer from various drawbacks. Barrierssuch as condoms and diaphragms are subject to failure due to breakageand displacement. Drug strategies, such as the pill and Norplant™, whichrely on artificially controlling hormone levels, suffer from known andunknown side-effects from prolonged use. Finally, surgical procedures,such as tubal ligation and vasectomy, involve the costs and attendantrisks of surgery, and are frequently not reversible. Thus, there remainsa need for a safe, effective method of contraception, particularly anon-surgical method which is reversible.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a contraceptive or sterilizationsystem for occluding a reproductive tract or lumen to prevent thepassage of reproductive cells through the tract or lumen. The inventionincludes an occluding member expandable within the body lumen from afirst configuration suitable for introduction into the body lumen to asecond larger configuration to facilitate securing the expandedoccluding member to at least a portion of a wall which defines thereproductive body lumen. The invention also includes means to facilitatesecuring the expanded occluding member to the wall of the body lumen andmeans to contract the expanded occluding member and the wall portionsecured to the occluding member to occlude the reproductive body lumensufficiently to prevent the passage of reproductive cells therethrough.

One presently preferred embodiment of the invention comprises areversible contraceptive system which can be used to occlude either thefallopian tubes of a female patient, the vas deferens of a male patientor other reproductive tract. A key feature of the contraceptive systemis a occluding member which is first secured to the wall defining thereproductive tract in an expanded condition and then is collapsed tosmaller transverse cross-sectional dimensions to cause the collapse ofthe secured portion of the wall and thereby block the vessel passagewayto prevent the passage of reproductive cells. The occluding member maybe reopened by any number of suitable means. For example, by collapsingthe occluding member about a plug or mandrel which can be left in placeto effectively blocking the passageway until the patient wishes toreverse the procedure. The plug can be removed by suitable means such asconventional laparoscopic or other instruments to reopen the passageway.A balloon dilatation catheter may be used to further expand the openingonce the plug is removed. Other ways of reopening the reproductive lumeninclude leaving the proximal portion of the occluding member open whenthe member is collapsed so that an expandable member such a balloon on acatheter can be inserted and expanded. By means of a series ofexpansions and stepped advancements, the entire passageway can bereopened.

Preferably, the occluding member comprises a tubular member formed froma shape-memory alloy material and has a primary configuration which isrelatively small in transverse dimensions to facilitate the insertion ofthe member into the desired body lumen. Once in place, the occludingmember is then expanded to a second configuration with transversedimensions roughly corresponding to or slightly larger than the bodylumen so that the occluding member can be secured to the wall definingthe body lumen. With the open, lattice-like framework of the occludingmember expanded within the body lumen, endotherlialization through theopen structure secures the occluding member to the wall defining thebody lumen. By heating the occluding member formed of shape-memory alloymaterial to a temperature at or above the transition temperature of theshape-memory material, it transforms to a remembered closed or collapsedconfiguration which causes the wall secured to the occluding member toclose down so that the passageway therethrough is occluded. Theoccluding member may be delivered to the desired location within thebody lumen by suitable means such as a conventional balloon cathetersimilar to those used for delivering stents, aortic grafts and varioustypes of prosthesis.

In one presently preferred embodiment, the occluding member has an openor lattice-like framework so that the growth of endothelial tissuethrough the openings of lattice-like framework so as to interconnect theoccluding member and the wall of the body lumen. The surface of theoccluding member may be treated to promote the endothelialization.

Once the occluding member is implanted into the body lumen and it hasbeen sufficiently endothelialized to secure it to the body wall (whichmay take a week or more), it may be activated by warming the occludingmember to a temperature at or above the transition temperature of theshape-memory material so it may revert to its remember constrictedshape. Since the endotheliaization has secured the occluding member tothe wall of the body lumen, the contraction of the occluding member toits remembered collapsed shape, causes the wall defining the body lumento collapse along with the occluding member, effectively blocking thepassageway. Alternatively, a plug may be located within the interior ofthe occluding member prior to heat activation so that the occludingmember collapses onto the plug to block the lumen.

The occluding member may be mounted onto the exterior of a balloon of adilatation balloon catheter in the first configuration with smalltransverse dimensions, and then be introduced and positioned within theregion of the reproductive lumen to be occluded. The balloon is inflatedto expand the occluding member, preferably with the outer diameterslightly larger than the inner dimensions of the reproductive lumen towhich it is secured. The occluding member will remain in the openconfiguration until heated to a temperature at or above its martensiteto austenite transition temperature which causes it to revert to itscollapsed state. If the occluding member is collapsed about a plug, theplug may be extracted to reopen the passageway when the patient wishesto become fertile again.

The present invention provides effective sterilization or contraceptionfor both males and females and importantly it is easily reversed.Moreover, the implantation and activation of the occluding member aswell as the subsequent restoration of vessel patency requires easilyused minimally invasive devices such as catheters, guidewires, guidingcatheters and the like. These and other advantages of the invention willbecome more apparent from the following detailed description of theinvention when taken in conjunction with the accompanying exemplarydrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a catheter with an occluding member embodyingfeatures of the invention mounted on an expandable member on a distalsection of the catheter.

FIGS. 2 and 3 show one embodiment of the occluding member in expandedand contracted or closed configurations respectively.

FIGS. 4 and 5 show another embodiment of the occluding member inexpanded and closed configurations respectively.

FIGS. 6 and 7 show yet another embodiment of an occluding member inexpanded and closed configurations respectively.

FIG. 8 depicts the occluding member on a delivery catheter as shown inFIG. 1 within a reproductive tract or lumen.

FIG. 9 illustrates the expansion of the occluding member within thereproductive tract or lumen.

FIG. 10 illustrates the female reproductive anatomy and shows theoccluding member positioned within one of the patient's fallopian tubes.

FIG. 11 illustrates the male reproductive anatomy and depicts anexpanded occluding member within a vas deferens of a male patient.

FIG. 12 illustrates the occluding member secured to the wall of thereproductive tract by endothelial tissue.

FIG. 13 is a transverse cross-sectional view of the expandedendotherlized occluding member as shown in FIG. 12 taken along the lines13-13.

FIG. 14 shows the occluding member in a collapsed state after beingactivated by warmed saline.

FIG. 15 is a transverse cross-sectional view of the collapsed occludingmember as shown in FIG. 14 taken along the lines 15-15.

FIG. 16 is similar to FIG. 14 and illustrates the occluding membercollapsed about an elongated removable plug or mandrel.

FIG. 17 shows the occluding member being activated in a location distalto the proximal extremity thereof in order to keep the proximal endpartially open to facilitate reopening the passageway.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a catheter 10 useful in the practice of theinvention, which comprises an elongated shaft 12 having an inflationlumen 14 which is in fluid communication with inflatable member 16mounted on a distal section of the catheter shaft and adapter 18.Occluding member 20, a self-supporting metallic member of shape-memorymaterial, closely conforms to the diameter of the uninflated inflatablemember 16 to facilitate introduction into the desired body lumen.Occluding member 20 is formed so that it has a remembered collapsedconfiguration with relatively small transverse dimensions. The occludingmember 20 may be deformed to facilitate mounting onto the inflatablemember 16 and is expanded by the inflatable member to an open expandedconfiguration within a body lumen. Upon heating to a transitiontemperature it will revert to the remembered configuration. In thisembodiment the occluding member 20 has an open, lattice-type structurefacilitating endothelialization which secures the occluding member tothe wall defining the body lumen. Preferably, occluding member 20 can bedeformed to an expanded diameter, preferably equal to or slightly largerthan the dimensions of the body lumen within which the occluding memberis to be disposed. For disposition within a female patient's fallopiantubes the expanded transverse dimensions should be about 0.1 mm to about5 mm.

The occluding member may have a number of suitable configurations asshown in schematically in FIGS. 2-7. FIG. 2 illustrates occluding member22 in an open configuration and FIG. 3 its relatively small dimensionedconfiguration for introduction and advancement into the patient's bodylumen. Occluding member 22 may be constructed from a length of shapememory hypodermic tubing. Slots 24 cut into the wall of the tubing allowexpansion of the occluding member into an open configuration as shown inFIG. 2. Likewise, in FIGS. 4 and 5, occluding member 26 is a coil 28 ofshape-memory wire or ribbon. FIGS. 6 and 7 show occluding member 30,which comprises a braided tube of shape-memory wire or ribbon 32.Finally, in FIGS. 1 and 8 occluding member 20 comprises a number ofclosed sinusoidal rings of shape-memory wire or ribbon and is mountedonto an inflatable member 16 of catheter 10.

Inflation of inflatable member 16 expands occluding member 20 in areproductive tract 38 to an open, relatively large diameterconfiguration as shown in FIG. 9. In each of these embodiments, theshape memory material of the occluding member should have a transitiontemperature sufficiently above the normal variation of human bodytemperature to prevent accidental activation which might prematurelycollapse the occluding member. On the other hand, the transitiontemperature should be high enough so that thermal activation of theoccluding member does not cause undesirable thermal damage to thesurrounding tissue. The shape memory-material is preferably a shapememory, nickel-titanium alloy such as NITINOL and preferably has atransition temperature of between about 43.degree. C. to about70.degree. C.

In each of the embodiments described above, certain conventionalrefinements may be employed. For example, the surface of the occludingmember's framework may be designed to facilitate endothelial growth.Such modifications generally comprise providing the occluding memberwith an open or lattice-like framework to promote endothelial growthinto as well as around the member to ensure it secure attachment to thewall of the body lumen. Suitable surface techniques include EDMmachining, laser drilling, photo etching, scintering and the like.Additionally, increasing the surface area of the occluding member canalso provide greater adhesion for the endothelial tissue. Suitablesurface treatments include plasma etching, sand blasting, machining andother treatments to roughen the surface. In other embodiments, theshape-memory material may be coated or seeded to spurendothelialization. For example, the occluding device can be coated witha polymer having impregnated therein a drug, enzyme or protein forinducing or promoting endothelial tissue growth. In yet anotherrefinement, the occluding member could be plated with or otherwiseincorporate copper to produce an inflammatory response in the tissue ofthe wall defining the body lumen, which further contributes to theobstruction of the lumen. Other inflammatory materials my be suitable aswell. For example, the occluding member could be radioactive, emittingalpha, beta or gamma particles.

The practice of the invention comprises the following general steps. Anoccluding member 20 having relatively small transverse dimension ismounted onto the exterior of balloon 16 of catheter 10 as shown inFIG. 1. The catheter 10 is advanced under fluoroscopic or endoscopicvisualization until occluding member 20 is positioned within one of thefemale patient's fallopian tubes 34, as shown in FIG. 10. Inflationfluid is introduced through adapter 18 to inflate inflatable member 16.As shown in FIGS. 9-10, inflation of inflatable member 16 expandsoccluding member 20 to an open configuration and lodging it in bodylumen 38. Catheter 10 is removed, leaving the expanded occluding member20 implanted in body lumen 38 as shown in FIG. 12. Another expandablemember is delivered to the patient's other fallopian tube and expandedtherein in the same manner. Alternatively, the occluding member may beexpanded into positioned within the vas deferens 36 of a male patient asshown in FIG. 11 to provide male contraception using the sameprocedures.

Over a period of a week or more endothelial cells lining the lumen willproliferate, growing around the open framework of occluding member 20 asshown in FIGS. 12 and 13 thereby securing the wall defining the bodylumen 38 to the expanded occluding member 20. After the expandedoccluding member 20 is sufficiently endothelialized within the patient'sreproductive tract 38, it is thermally activated to return it to itsremembered collapsed configuration. The occluding member may beactivated by several means, including warmed fluid, RF energy, laserenergy, or other suitable energy sources. A suitable activation systemis shown in FIG. 14 where the distal end of catheter 40 is positionedadjacent to the occluding member 20, saline fluid somewhat above thetransition temperature is introduced to bathe occluding member 20,raising its temperature to the transition point or higher, causingoccluding member 20 to collapse to its closed, reduced-diameterconfiguration. The layer of endothelial tissue that forms within thelattice-like structure of the occluding member helps block and seal thelumen so as to prevent the passage of reproductive cells, eggs or spermcells.

In an alternative embodiment of the invention is shown in FIG. 16 wherea plug 42 is positioned inside occluding member 20 in the expandedcondition so that upon activation the occluding member 20 collapses ontoplug 42, blocking the lumen 38. The plug is preferably formed from aninert material such as a fluoropolymer, e.g. PTFE. Other suitablematerials include high density polyethylene and silicone rubber. Anumber of modifications to the plug may also be suitable. For example,the plug could be used as a drug delivery device, similar to theNorplant™ device. The plug could also be used to provoke an inflammatoryresponse as described above to augment the occlusion of the lumen. Insuch embodiments, plug 42 preferably has an outer diameter from about0.25 mm to about 4 mm. The plug 42 may also have holes, deep grooves orwhich help to preserve at least part of the natural lining of thereproductive tract.

The occlusion of the lumen may be reversed simply by removing the plug42. If a passageway larger than passageway left by the removed plug 42is desired, a balloon catheter can be advanced within the body lumenuntil the balloon is within the lumen left by the removal of the plugand then the balloon on the catheter is inflated to expanded theoccluding member 20, deforming it into an open configuration. It may bedesirable when activating the expanded occluding member to the collapsedconfiguration to leave the proximal end of the occluding member somewhatopen or in an expanded condition to facilitate the introduction ofdilatation balloon on a catheter to facilitate the opening of the bodylumen. As shown in FIG. 15, the catheter 40 used to activate theoccluding member may be positioned within the proximal end of theoccluding member, so that the proximal end is unable to completelyrevert to its closed configuration. The reproductive tract could besubsequently close should contraception again be desired by heating theoccluding member 20 so as to activate the transformation thereof to thecollapsed configuration.

In embodiments of the invention employing the plug 40, various otherstrategies are suitable to reverse the occlusion. For example, the plug40 can simply be removed, restoring the lumen 38 to patency.Alternatively, the plug 40 may be hollow with a removable core (notshown). This core may be formed from a softer material, such assilicone, or could be threaded, in order to facilitate its removal.Similarly, the plug itself may be threaded so that removal wouldcomprise a twisting motion, minimizing the stress on the tissue in whichthe occluding member is located.

In still other embodiments, mechanical, adhesive or other means may beemployed to secure the expanded occluding member 20 to the vessel walldefining the reproductive passageway 38. For example, the means tosecure a stent or prosthetic device to an aortic or arterial walldescribed in U.S. Pat. No. 4,140,126; U.S. Pat. No. 4,562,596; U.S. Pat.No. 4,577,631; U.S. Pat. No. 4,787,899; U.S. Pat. No. 5,104,399; U.S.Pat. No. 5,167,614; U.S. Pat. No. 5,275,622; U.S. Pat. No. 5,456,713;and U.S. Pat. No. 5,489,295 may be used with the present invention tointerconnect the wall defining the reproductive tract and the expandablemember. These patents are incorporated herein in their entireties byreference.

Various modifications and improvements may be made to the presentinvention without departing from the scope thereof. For example, amechanical expandable member such as described in U.S. Pat. No.4,585,000, which is incorporated herein by reference, may be used toexpand the expandable member within the reproductive tract to engage thewall thereof. Moreover, although individual features of embodiments ofthe invention may be shown in some of the drawings and not in others,those skilled in the art will recognize that individual features of oneembodiment of the invention can be combined with any or all the featuresof one or more of the other embodiments.

1. A contraceptive or sterilization system for occluding a reproductivebody lumen to prevent the passage of reproductive cells therethrough,comprising: a) an occluding member which is at least in part expandablewithin the reproductive body lumen from a first configuration to asecond larger configuration to facilitate securing the expanded portionof the occluding member to a wall portion which defines at least in partthe reproductive body lumen; b) means to secure the expanded portion ofthe occluding member to the wall portion; and c) means to contract theexpanded portion of the occluding member so that the wall portionsecured thereto likewise contracts to occlude the reproductive bodylumen sufficiently to prevent the passage of reproductive cellstherethrough.
 2. A method for sterilizing a female patient by occludingthe patient's fallopian tube, comprising: a) reducing transversedimensions of at least a portion of the patient's fallopian tube; b)maintaining an occlusive body within the portion of the patient'sfallopian tube having reduced transverse dimensions, wherein saidocclusive body is configured to provoke an inflammatory response in thepatient's fallopian tube.
 3. The method of claim 2 wherein thetransverse dimensions of a portion of the patient's fallopian tube arereduced by securing a tubular member to the fallopian tube andcollapsing the tubular member.
 4. The method of claim 3 wherein thetubular member has an open-wall structure.
 5. The method of claim 4wherein the tubular member is formed of shape memory alloy which has astable martensite phase at body temperature, has a first smalldimensioned configuration facilitating the introduction thereof into alumen of a patient's reproductive system, is expandable to a secondlarger configuration facilitating securing a least a portion of thetubular member to a wall portion of the patient's fallopian tube, has anopen-wall structure facilitating tissue ingrowth thereby securing theexpanded portion of the tubular member to the wall portion and has acontracted remembered shape in an austenite phase at temperatures higherthan body temperature with a remembered configuration having smallertransverse dimensions than the second larger configuration.
 6. Themethod of claim 5 wherein tissue ingrowth into the open-wall structureof the tubular member secures to the tubular member to an interiorportion of the patient's fallopian tube.
 7. The method of claim 2,wherein occlusion of the fallopian tube is augmented by tissue ingrowth.8. The method of claim 7 wherein the occlusive body is maintained in thereduced diameter portion of the fallopian tube for sufficient time toallow tissue ingrowth.
 9. The method of claim 2 wherein the inflammatoryresponse is provoked by a copper element associated with the occlusivebody.
 10. The method of claim 9 wherein the transverse dimensions of thepatient's fallopian tube are reduced by securing a tubular member withinthe patient's fallopian tube and collapsing at least a portion of thetubular member.
 11. The method of claim 10 wherein the tubular memberhas an open wall structure to facilitate tissue ingrowth to secure thetubular member to the fallopian tube.
 12. The method of claim 11 whereinthe tubular member is formed of shape memory material and the collapsedstate is a remembered shape.
 13. The method of claim 12 wherein theocclusive body contains grooves.
 14. The method of claim 13 wherein theocclusive body contains holes.
 15. The method of claim 14 wherein thecopper element is associated with said holes.
 16. The method of claim 13wherein the copper element is associated with said grooves.